The U.S. Army Corps of Engineers operates 12 thousand miles of commercial waterways across the country. Dams along these waterways generate power and also play a critical role in reducing the risk of flooding. Mary Cochran takes us to an important dam on the West Coast.More information on the Howard Hanson Dam at: www.nws.usace.army.milGet live updates at: http://twitter.com/HowardHansonDam